Douglas Isbell
Headquarters, Washington, DC August 26, 1997
(Phone: 202/358-1753)
Sally Koris
TRW Space & Electronics Group, Redondo Beach, CA
(Phone 310/812-4721)
RELEASE: 97-182
LEWIS SPACECRAFT ENCOUNTERS DIFFICULTIES
NASA's Earth-orbiting Lewis spacecraft has entered a
spin that has disrupted the spacecraft's power-
generating capability, raising the potential of the loss
of the mission.
Lewis was launched successfully on Aug. 22 at 11:51
p.m. PDT from Vandenberg Air Force Base, CA, aboard a
Lockheed Martin Launch Vehicle (LMLV-1). Built by TRW
Space & Electronics Group, Redondo Beach, CA, Lewis is
part of NASA's Small Spacecraft Technology Initiative.
Initial operations and check-out of Lewis were
proceeding satisfactorily until telemetry received at 6
a.m. EDT today at the mission's Chantilly, VA, control
center indicated that the spacecraft was spinning at
approximately two revolutions per minute. Preliminary
indications are that excessive thruster firing had
occurred on one side of the spacecraft, causing it to
spin when it should be stable on all three axes.
The solar arrays on Lewis were unable to generate
full power due to the spinning motion, and the batteries
were discharged below operational levels. Four
subsequent attempts to contact the spacecraft were
unsuccessful.
"The excellent performance of the launch vehicle put
Lewis into an optimal circular parking orbit that
provides us with a minimum of three weeks to try to
resolve this anomaly," said
Samuel Venneri, Chief Technologist at NASA Headquarters
in Washington. "In addition, Lewis carries several
autonomous systems onboard that raise the possibility
that it can correct itself and recharge the batteries.
NASA and TRW are working hard to assess and better
understand the situation, in order to establish a
recovery plan and try to resume the mission."
Outfitted with advanced technology Earth-imaging
instruments and subsystems intended to push the state-
of-the-art in scientific and commercial remote sensing,
Lewis features remote sensing instruments designed to
split up the spectrum of light energy reflected by
Earth's land surfaces into as many as 384 distinct
bands. Potential commercial applications include
pollutant monitoring, analysis of endangered species
habitats, estimation of forest and agricultural
productivity, soil resources and crop residue mapping,
and assessments of environmental impacts from energy
pipelines.
The total cost to NASA of the Lewis mission,
including its launch vehicle and one year of orbital
operations, is $64.8 million. NASA incurred an
additional cost of $6.2 million for storage and
maintenance of the spacecraft during a one-year delay
due to launch vehicle issues.
Lewis is part of NASA's Mission to Planet Earth
enterprise, a long-term research program designed to
study the Earth's land, oceans, air and life as a total
system.
-end-